Stabilizing lattice oxygen and interface chemistry of Ni-rich and Co-poor cathodes for high-energy lithium-ion batteries

Abstract

Development of Ni-rich and Co-poor cathodes (Ni ≥ 80%, Co ≤ 5%) is indispensable for the next-generation lithium-ion batteries (LIBs) owing to the anxiety of electric vehicles about the scarce...

Perovskite Oxides Alleviate Microstrain and Anion Loss of Radially‐Aligned Ni‐Rich Ncm811 Cathodes under High‐Voltage Operations

“…This is because the coating layer with abundant oxygen vacancies of LC‐NCM811 can effectively hold oxygen free radicals, and return it back to bulk in the subsequent discharging process. [ 12,26 ] In addition, the DSC results show that the LC‐NCM811 exhibits higher peak value of self‐exothermic temperature (260.76 vs 208.78 °C) and lower heat release (87.82 vs 318.99 J g −1 ) compared with NCM811 (Figure 4i). Thus, this perovskite oxides strategy eliminates lattice oxygen release and remarkably alleviates the thermal runaway, improving the security of Li‐ion batteries.…”

“…Meanwhile, the coating layer La x Ca 1− x [TM]O 3− x often has abundant oxygen vacancies, [ 12 ] which can store the unstable oxygen radicals (O 2 2− ) under high voltage, avoiding oxygen radicals correlated side reactions during de‐/lithiation. [ 10,26 ] In the subsequent discharge process, they can re‐release and from M─O bonds. Such synergistic advantages are expected to greatly enhance the structural stability and eliminate the interface side effects with electrolyte, leading to a long‐term cycle life.…”

Enhanced Li-ion intercalation kinetics and lattice oxygen stability in single-crystalline Ni-rich Co-poor layered cathodes

“…This observation demonstrates the successful incorporation of Ba ions and Al ions into the layered structure of NCM85. 24,28 According to the fast Fourier transform (FFT) model, they are good hexagonal layered structures. High-angle annular dark eld (HAADF) images and corresponding elemental mapping demonstrated a uniform distribution of Ni, Mn, Co, Ba, and Al (Fig.…”

Low‐Electronegativity Cationic High‐Entropy Doping to Trigger Stable Anion Redox Activity for High‐Ni Co‐Free Layered Cathodes in Li‐Ion Batteries

“…However, oxygen redox in TM layer is always accompanied by the anionic redox irreversibility and structure instability, leading to the formation of O 2 . [3,[32][33][34] Then, the irreversible O 2 release caused by over oxidation of oxygen ions will provoke the collapse of anionic framework. Subsequently, due to the absence of interaction between oxygen and TM ions, further migration of TM ions appears, leading to collapse of the TM layer and electrochemical performance degeneration.…”